Early increase in pulsatile growth hormone release after unilateral nephrectomy in adult rats.
Early increase in pulsatile growth hormone release after unilateral nephrectomy in adult rats.
复制标题
成年大鼠单侧肾切除术后脉动生长激素释放的早期增加。
DOI：
10.1152/ajprenal.1994.266.4.f628
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Mulroney,SE
中科院分区：
文献类型：
--
作者：
Haramati,A;Lumpkin,MD;Mulroney,SE
切除一个肾脏会在几天内导致剩余肾脏的加速生长。然而，这种代偿性肾肥大反应的机制，特别是在肾切除术后的早期，还不清楚。在这项研究中，我们测试的假设，即删除一个肾脏导致的变化，在脉动释放生长激素（GH），这有利于代偿性肾脏生长。成年Wistar大鼠颈静脉内植入硅橡胶套管，并进行单侧肾切除术（UNX）或假手术。在假手术或UNX后24和48 h测定血浆GH水平。在6小时的时间内，每20分钟从清醒、不受约束的动物中采集血样。脉冲GH释放显着升高24小时后UNX的浪涌的幅度以及在释放的持续时间。UNX大鼠24小时后的GH峰值水平是假手术对照组的3 - 4倍（417 +/- 75 vs. 119 +/- 23 ng/ml，P < 0.05）。然而，这种增强的GH释放似乎持续时间较短，并在UNX后48小时开始下降（峰值水平为227 +/- 37 ng/ml，P < 0.05，与24小时UNX和假手术对照相比）。为了检查UNX后GH释放的这种增加是否有助于代偿性肾生长，大鼠经历UNX并立即用GH释放因子的拮抗剂（GRF-AN;即，[N-Ac-Tyr 1，D-Arg 2]GRF-（1-29）酰胺，200 μ g/kg，每日两次），并测定对GH释放和肾脏生长的影响。GRF-AN给药显著抑制了UNX后GH释放的增加，并与GRF-AN治疗大鼠UNX后48小时肾脏生长的显著减弱相关（8.7 +/- 2.6% vs. UNX对照组22.7 +/- 3.0%，P < 0.05）。（250字处删节）
Removal of one kidney results, within days, in accelerated growth of the remaining kidney. However, the mechanisms that underlie this compensatory renal hypertrophic response, particularly in the early time period following nephrectomy, are not understood. In this study we tested the hypothesis that removal of one kidney leads to a change in the pulsatile release of growth hormone (GH), which facilitates compensatory renal growth. Adult Wistar rats were implanted with Silastic cannulas in jugular veins and underwent either unilateral nephrectomy (UNX) or sham operation. Plasma levels of GH were determined 24 and 48 h after sham operation or UNX. Blood samples were taken every 20 min over a 6-h period from conscious, unrestrained animals. Pulsatile GH release was markedly elevated 24 h after UNX in both the amplitude of the surges as well as in the duration of release. Peak GH levels after 24 h were three- to fourfold higher in UNX rats compared with sham controls (417 +/- 75 vs. 119 +/- 23 ng/ml, P < 0.05). However, this enhanced release of GH appeared to be of short duration and began declining by 48 h post-UNX (peak level of 227 +/- 37 ng/ml, P < 0.05 vs. both 24 h UNX and sham controls). To examine whether this rise in GH release post-UNX contributed to the compensatory renal growth, rats underwent UNX and were immediately treated with an antagonist to GH-releasing factor (GRF-AN; i.e., [N-Ac-Tyr1,D-Arg2]GRF-(1-29) amide, 200 micrograms/kg twice daily), and the effects on GH release and renal growth were determined. Administration of GRF-AN significantly suppressed the increase in GH release post-UNX and was associated with a significant attenuation in renal growth 48 h post-UNX in GRF-AN-treated rats (8.7 +/- 2.6% vs. 22.7 +/- 3.0% in UNX controls, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)